Motor.



3 SHEETS-SHEET l.

PATBNTED AUG. v18, 190s. E. H. HERNDON.

MOTOR.

APPLICATION FILED JULY 10,1907.

i N 1i W liv ' PATENTED AUG. 18, 1908.

E. H. HERNDON.

MOTOR.

APPLICATION FILED JULY 10,1907.

3 SHEETS-SHEET 2.

www@

A TTG/emi ys PATENTED AUG. 18, 1908.

E. H. HERNDON.

MOTOR.

APPLICATION FILED JULY 10,1907.

3 SHEETS-SHEET 3.

UNITED sTATEs PATENT oEEroE.

EMMETT H. HERNDON, OF SANFORD, FLORIDA.

MOTOR.

To all whom it may concern:

Be it known that I, EMMETT H. HERNDON, a citizen of the United States, residing at Sanford, in the county of Orange and State erate'd byiluids under pressure, such for in stance as the gases generated by the ignition of an explosive compound. o

The invention com rises an engine in which there is provided a s aft carrying a rotative member with a helical return groove, and parallel with the axis of the rotative member is a cylinder or cylinders, each containing-a reciprocating piston with a projectionat an intermediate point thereon and entering the groove after passing through a slot in a guiding member. The projection carries antifriction rollers one against the walls of the groove and the other incased in the walls 0f the slot. Furthermore there are hollow exhaust heads having bearings to serve for the engine shaft and the engine cylinders have their exhaust ports opening into the heads. The invention also consists in certain novel features of construction and arran ement of parts, hereinafter fully described, ilustrated 1n the. accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions, size and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantages of thel invention.

In the accompanying drawings Figure 1 is a side elevation of a motor constructed in accordance with the invention, one of the cylinders being shown in section and parts being broken away and some parts omitted. Fig. 2 is a transverse sectional view of the motor on the line 2 2 of Fig. 1. Fig. 3 is a detail sectional view ofnone of the shaft bear; ings. Fig. 4 is a transverse sectional view of the shaft showing the spark timer. Fig. 5

is a detail view, partly in section showing a preferred form of shaft and piston connection. Fig. 6 is a sectional elevation, partly in the nature of a diagram, showing the arrangement of the cooling devices. Fig. 7 is a diagram showing the operation of the main and auxiliary pistons.

Specification of Letters Patent. Application led July 10, 1907. Serial No. 383,056.

Patented Aug. 18, 1908.

Similar numerals of reference are' employed to indicate corresponding parts throughout the several figures of the drawings.

The general frame of the machine includes a pair of approximately triangular boxes 10, which are rigidly secured together by a cylindrical shell 11. At the center of each of the boxes is a bearing for the support ofthe shaft 15, and each box is provided with semi-circular depressions 16 for the reception of the cylinders 17, three pairs being shown in the present instance, the cylinders being c011- fined in place by straps 18 and other securing devices, if necessary.

` The boxes 10 are hollow and constitute exhaust heads which are in free communication with the cylinders through ports 20, the latter being arranged to open when the piston reaches the limit of the working stroke, and both boxes communicate with a muffler 21 having a discharge pipe 22 through which the products of combustion from all of the cylinders finally escape.

In order to prevent undue heating ofthe shaft bearings, the central portion of each of theboxes is arranged to receive a hollow ring 23 through which air is circulated in the man` ner hereinafter described, and the inner wall of each ring is provided with threads for the reception of ball races 24, these serving in connection with ball races 25 on the shaft 'for the reception of-anti-friction balls 26.

Secured rigidly to the shaft at a point between the two boxes is a drum 27 that is provided with a return helical groove 28 of such pitch that there will not be undue friction be- 'actuated members which enter such groove.

The cylinders are arranged in pairs, those constituting each pair being arranged with their axes in alinement yand within each pair of cylinders fits double ended pistons 29. Projecting from the central portion of each piston is a stud 30 carrying two anti-friction rollers 31 and 32, all'of the rollers 32 entering the helical groove of the drum 27, while all of the rollers 31 are arranged for contact with the walls of the slots 33 that are formed in the c lindrical shell 11. These slots 33 extend ongitudinally of the shell and are parallel with the axes of the shaft and cylinders, so that they serve to maintain the studs 30 in proper position and prevent any turning of the pistons on theiraxes, so that the pistons proper are not subjected to any torsional strain from the engagement of the rollers 32 with the walls of the helical slot 28.

Each of the pistons 29 is preferably in the form of a hollow cylinder closed at both ends and preferably of uniform diameter throughout its entire length, although it may be in the form of a pair of piston heads connected by a stem of less diameter than the heads.

Each of the cylinders is of precisely the same construction, the explosion chamber having a cap or cover 38 from which extends a tube 39, the axis of which is coincident with that of the cylinder. Through this tube passes a rod 4() carrying at its inner end an auxiliary piston 41 in which are formed one or more transverse ports 42. These ports are provided with valves 43 that are normally held in closed position by springs 44 coiled around the valve stems and bearing at one end against the piston and at the opposite end against adjustable nuts carried by the stem. The outer end of the rod 40 carries a hook 45 to which the outer end of a tension spring 46 may be attached, the inner end of the spring being connected to an eye on the head of the explosion chamber, the hook projecting through an elongated slot 47 formed in the wall of the tube 39, and said spring tending at all times to force the auxillary piston 41 away from the head of the eX` plosion chamber. y

Projecting from the stem 40 is an antifriction roller 48 that is mounted on a stem 4 9 passing through a slot 50 formed in tube 39. a cam 51 on the shaft, the shaft being provided with two cams one for each set of 'operating cylinders at each end of the motor.

At the explosion chamber head is an inlet 53 leading from the carbureter or other source of supply and through which the explosive compound is admitted to the cylinder. Arranged slightly in advance of each auxiliary piston is a sparker 54 of any ordinary construction, provision being made for controlling the igniting circuits in order to ,advance or retard the spark, as desired. v

yIn the operation of the motor as a two cycle engine reference is had to the cylinder shown in Fig. 1, wherein the piston 29 is traveling toward the right and has nearly reached the end of the working stroke, it being observed that the esca e port 20 of the left hand cylinder is nearly fiill open. During this working stroke the pressure of ases within the cylinder has kept the auxi iary piston stationary, although the roller 48 of the latter is at this time out of engagement with its operating cam 51. As soon, however, as the port 20 opens to such an extent as to permit the artial discharge of the explosive compoun the pressure 1n the cylinder will reduce to a point below the stress exerted by the spring 46, which at this time This roller is arranged to be engaged by l has been placed under tension. When the pressure reduces to a oint below the strength of the spring, the atter in retracting will force the auxiliary iston inward toward the exhaust ort, there y forcing out the remainder of t e explosive charge, and, at the same time, creating a partial vacuum at the explosion chamber end of the cylinder, thereby causing an inflow of an explosive charge, and during this movement the valves 43 will remain closed in order to prevent the admixture of the fresh charge with the exploded gases.

As the anti-friction roller of the piston makes the turn in the helical groove 28, the roller 48 of the auxiliary piston will be engaged by the cam 51 and the auxiliary piston will be moved outward by the cam in advance of the iston 29, as will be evident on reference to t e diagram Fig. 7, where the inclination of the cam is shown to be much quicker than the inclination of the groove, so that fthe auxiliary piston will arrive at the end of its out stroke or the stroke towards the explosion chamber head long before the main piston completes its stroke in the same direction. During this out stroke of the auxiliarjv piston the valves 43 open and the fresh charge passes to the space between the two pistons and is compressed therebetween as the main piston com letes its stroke, and at the end of this stro e the fresh charge of compressed explosive compound is ignited by the spark lug and another working stroke is ei'ecte( Around the explosive chamber of each cylinder is arranged a plurality of air circulati 0 passages 60, all of which are approximaflely semi-circular in cross section, although the shape is unimportant. These passages are connected to headers 61 and 62 of which the headers 62 are connected to the air jackets 23 around the shaftbearings. Each jacket 23 is provided with a dia hragm 66 and is connected at one side of t e diaphragm to a fluid sup ly pipe 67 through which air or other coo ing uid is directed, the air passing through the ackets and thence to the headers 62, after which the air flows through the passages 60 to the headers 61 for the pur ose of reducing the temperature-of the exp osion chamber.v The exhaust air from the headers passes through pipes 68 to a nozzle 69 that is arranged at the axis of the discharge ort 22 of the muffler, so that the jet of disc arging air may act after the manner of an inspirator for the purpose of causing an outflow of the exhaust gases from the muffler and the exhaust boxes 10. This, of course, will create a slight vacuum within the boxes 10 so that the exhaust may freely pass through the ports 20 from the cylinders.

The sparking apparatus is preferably in the form of a ring 70 mounted in an annular bearing 71 surrounding and concentric with the shaft, there vbeing two of such rings 70, one at each end of the motor, and each ring carrying a number of sets of terminals 72 corresponding to the number of cylinders. These terminals are arranged to be engaged by a pin 7 3 projecting from the shaft, and as thelatter rotates the terminals will be ysuccessively engaged for the purpose of first closing and then opening the circuits and thus producing the sparks at the sparking plug. The ring 70 is mounted in a bearing 75 and is provided with a handle 76 by which it may be turned for the purpose of advancing or retarding the spark as may be required.

When the engine is to be operated on the four cycle principle the spring 46 is detached from the hook 45 and the rod 40 is locked to the tube 39 so as to prevent movement of the auxiliary piston 42, the rod 40 being provided with an opening 79 into which a suitable pin may be inserted for this purpose. The device will then operate as an ordinary four cycle engine with the exception that the exhaust port will be under the control of the main piston and will be opened by the piston when the latter reaches the limit of the Working stroke. Owing to the partial vacuum creat-d in the exhaust passages as hereinbefore described, the major portion or all of the exploded charge will be withdrawn from the cylinder at the end of the working stroke, so that the piston is freeto return to the explosionl chamber end of the cylinder in readiness for the following suc.- -tion stroke.

In the construction of large engines, it is preferred to employ double grooves 28i and for this purpose the drum proper is provided with a 'helical return rib 80, and on said drum are mounted two sleeves 81, the ends of which follow the contour .of the rib and are spaced therefrom to form the two grooves 28. These sleeves may be adjusted toward and from the central rib by means of tapered keys 83 that-extend through slots formed-in the sleeves and drum, the keys being preferably provided with laterally projecting arms 84 through which pass bolts or screws 85 that fit within threaded openings neari the end portions of the drum. This provides for taking up any wear which may occur in the walls of the grooves. The single groove drum is also provided with adjusting means, one or bot-h of the sleeves which form the walls of the slot being ady justable to compensate for wear.-

4 the muliier, thelatter is preferably provided In Fig. 1 keys 83 are shown for both members of the drum 27. In the structure of Fig. 1 the keys and controlling means therefor mayv be the same as those shown in Fig. 5. n

In order to prevent danger of explosion in with a safety valve 88 which may be opened which the engine is adapted to operate, may

be used.

I claim 1. In a motor, a rotative member having a helical return groove, the walls of said groove being adjustable to compensate for wear, a pair of axially alined cylinders, a double ended piston mounted in said cylinders, a stationary guide having a slot, the walls of which are parallel with the axes of the cylinders and the rotative member, a stud projectin from thepiston, and a pair of anti-friction ro 1ers, carried by the stud, one of such rollers engaging the walls of the groove, and the other the walls of the slot.

2. In a motor, a shaft, a member' thereon having a helical return groove, a pair of hollow exhaust heads having supporting bearinv s for the shaft, a pair of axially alined cy inders carried by said heads and provided with exhaust ports in communication with the heads, a double ended piston mounted in the cylinders, and a projection extending from the piston and entering the groove.

3. In a motor, a pair of spaced hollow exhaust heads, bearings carried by said heads, a shaft mounted in said bearings, a member on the shaft provided with a helical return groove, a pair of axially alined cylinders rigidly secured to said heads and having exhaust ports in communication with the heads, a piston mounted in the cylinders, a fixed guide extending between and connect-v ing the heads, said guide having a longitudinal slot, the Walls of which are parallel with the axes of the cylinders, a stud projecting from the piston, and a pair of anti-friction rollers carried by the stud, one of the rollers engaging the walls of the groove and the other the walls of the slot.

4. In a motor, a pair of spaced hollow exhaust heads, bearlngs carried thereby, a shaft mounted in said bearings, a member on they shaft provided with a helical return groove, a cylindrical shell surrounding thev heads, each having a separate opening, an annular cooling jacket mounted in said o pening, ball races supported by the jacket, a shaft also having ball races, anti-friction balls mounted in the ball races, a member on the shaft provided with a helical return groove, a pair of axially alined cylinders supported by the heads and provided with exiaust ports in communication therewith, cooling jackets surrounding the cylinders, air circulating connections between the cooling jackets around the bearings and those around the cylinders, a' piston mounted in the cylinders, and a projection extending from the piston and entering the groove.

6. In a motor, a pair of spaced hollow exhaust heads, each having a central opening, a cooling jacket mounted in said openin ball races sup orted by the jacket, a sha t also having ba l races, a member on the shaft provided with a helical return groove, antifriction balls mounted in the races, a pairof axially alined cylinders rigidly su ported by the exhaust heads and having ex aust ports in communication with said heads, a double ended piston mounted in said'cylinders, a projection extending from the piston and entering said groove, an air jacket surrounding cach cylinder and comprising a pair of headers and intermediate connecting passages,`

and air circulating connections between the cooling jacket around the bearings and the headers.

7j. In an engine of the class described, a shaft, a drum thereon, a pair of spaced sleeves on the drum each arranged to form one edge or wall of a helical groove, means for adjusting said sleeves to take up wear, a cylinder, a reciprocating piston therein, and

means extending from the piston into e111v gagement with the groove walls of the adjustable sleeves.

8. In an engine of the class described, a shaft, a drum thereon, a pair of sleeves mounted on the drum, one end wall of each sleeve constituting one wall of a helical groove, tapered keys extending through openings in the sleeves and drum, means for adjusting said keys to compensate for Wear on the groove walls, a reciprocatory piston, and means extending from said piston into operative relation with the groove walls.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses` EMMETT H. HERNDON.

Witnesses:

E. HUME TALBERT, JNO. E. PARKER. 

